PlanetCatfish.com

question for the scientists:

how can you see the difference between and when the fish in question is just 4-5" SL, or 6" TL?

they sure look alike.....is there a visible difference apart from number of scutes or something?

For us aquarists it is difficult, especially when the key in Sabaj et al 2008 separates the two species by internal differences. If you haven't already got it there is a table in that publication which may help you:

Sabaj Pérez, M. H. , D. C. Taphorn, and O. E. Castillo G. 2008
Two new species of thicklip thornycats, genus Rhinodoras (Teleostei: Siluriformes: Doradidae). Copeia 2008 (no. 1): 209-226.

You hint about number of scutes so you may have it already. Looks like boehlkei has 61-64 midlateral plates and dorbignyi 55-60. The publication also states boehlkei has the dark saddle bars more contrasted than dorbignyi, but that in its own can be misleading to the eye.

Not always that easy to tell, but one difference would be where they came from.

I will ask Mark Sabaj if there is any easily determined external keys.

Edit: The.Dark.One gave as good an answer as I could expect to get from Mark, so I won't ask... .

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Mats

too bad that article is not a link; I only got an abstract of a Spanish article on Leptodoras when I googled it.

my Spanish is non existent......especially when it's scientific.

pm me your email address and I'll send you a pdf

sidguppy wrote:my Spanish is non existent......especially when it's scientific.

Odd

Having spend a few years on learning Spanish, I find the instructive texts are rather easy to read, but I still not dare reading novels

Why? Because scientific Spanish uses many words which are quite similar in English, and the grammar is not that complicated while everyday Spanish is quite complicated indeed

Sit and read a bit I'd say

good thing Steve send me an article in plain English; thanks Steve!